Drum-type sander



June 25; 1929. RAfSOLEM 1.718.839

DRUM TYPE SANDER Filed March 19, 19 27 2 Sheets-Sheet l June 25, 1929. P. A. soLEM DRUM TYPE SANDER Filed March 19, 192'? 2 SheetsShee1;

Patented June 25, 1929.

UNITED STATES PETER A. SOLEM, OF ROCKFORD, ILLINOIS.

DRUM-TYPE SANDER.

Applieation filcd March 19, 192?. Serial No. 176,618.

This invention relates to abrading machines and is more particularly devoted to improven'ients in drum type sanders for woodworking.

In machines of the kind mentioned the drums are mounted for vertical adjustment according to the depth of cut to be made. The principal object of the present invention is to provide three-point supports for each of the jmirnal bearings of the drums so as to provide a rigid mounting in any position of adjustment of the drums and eliminate vibration and chattering in operation and accordingly improve the character of the finish produced on the work. The details of construction for accomplishing the foregoing result are also a substantial in'iproveinent over previous constructions in that the parts are easier to machine to a proper fit and are likewise easier to assemble. This, of course, makes for greator economy in production.

Still another important object of the invention is to provide top plates extending crosswise of the machine over the drums serving rigidly to interconnect the journal bearings for the opposite ends of each of the drums whereby further to cut down vibration in the operation of the machine. Each of these plates provides thrust bearing surfaces fore and aft with respect to a drum and is open intermediate the bearing surfaces not only to afford access to the drum for the replacement of the abrasive covering but also to admit air to entrain the dust arising from the performance of the sanding operation, the said top plates being cut away adjacent the aforesaid thrust bearing surfaces to provide dust exhaust openings. The present invention is, however,-not particularly concerned with the method of exhausting the dust from the machine, this subject matter being covered in l another application.

Another feature of the invention resides in the provision of pressure bars between the drums as well as in front of the foremost drum and behind the rearmost drum, the lat ter two pressure bars being extended upwardly into the plane of the top plates and providing thrust bearing surfaces to cooperate with the thrust bearing surfaces of the foremost and rearmost top plates, the said foremost and rearmost pressure bars being adjustably mounted on the frame to permit moving the same inwardly toward each other untilall ofthe thrust bearing surfaces of the group of top plates are in close contaetand the smooth and quiet operation of the machine thereby insured. i

The invention embraces other objects and advantages which will appear in the course of the following description in which refer ence is made to the accompanying drawings whereini Figure 1 is a side view of a sander of th endless bed type wherein the entire top portion has been improved in accordance with my invention;

Fig. 2 is a plan view of Fig. 1 showing only the right hand half of the machine without the bed; and

Fig. 3 is a central. vertical section through the top portion of the machine.

Throughout the views the same reference numerals are applied to corresponding parts.

Drum type sanders are usually constructed with a base 5 having heavy upright side frame frame pieces 6 suitably fixed together in spaced relation. The frame provides supports for ways over which an endless bed 7 is alfanged to move, the bed consisting of steel slats with rubber pads secured thereon and the slats being secured on roller chains operating on sprockets mounted on bearings at 8 and 9 at opposite ends of the machine. The.

bed is driven through suitable. transmission from a shaft 10 which in turn is driven by a motor supported on a bracket at the far side of the machine. A pulley 11 on the shaft 10 is provided for driving pulleys l2 and 13 which operate brushes for cleaning the stock passing through the machine and for cleaning the bed The brush for cleaning the stock is indicated at 14; and will receive further mention hereinafter. The belt 15 passing about the pulleys referred to has an idler takeup pulley 16.. A plurality of rotary abrading drums 17, 18 and 19 operate over the bed 7 and are provided with individual driving motors (not shown) arranged to be controlled singly or collectively to givea one, two or three drum machine as desired, and to permit any one or more or all of the motors being started or stopped as desired. Usually the front drum of the set,namely the drum 17, is given simple rotation for the initial rough finishing cut inasmuch as it operates at the intake end ofthe machine. The other drums which arerearwardly located with reference to the drum 17 are arranged to have endwise oscillation or reciprocation during rotation in order that the grade of finish on the work may be improved by avoiding the drawing or stringing out of the fibers ofthe Wood in a loose fuzz or fur. Thus, the drums 18 and 19 are oscillated by rocker arms or beams 20 which have a suitable thrust bearing connection with the projecting journals of the drums, as at 21. The rocker armsare suitably oscillated on their mountings 22 by cams on the shaft 23 which is suitably driven through a direct gearing connection with the shaft 10. In this way the oscillating motion of the drums 18 and 19 occurs only during the feeding movement of the endless bed 7, that is during the normal operation of the machine.

. Each of the drums has its projecting journals received inbearings 24 and the drums are individually adjustable as to elevation for light or heavy cuts by the turning of jack screws 25 provided in connection with the journal bearings 24 of each drum. The pair of jack screws for each drum are usually interconnected for simultaneous operation so as to elevat'e both ends of the drum to equal degrees. For the most part, the foregoing arrangement is commonly employed in sanding machines of the drum type and no invention is claimed therein except only in so far as the improvements hereinafter referred to rely upon these features in the new combinations and arrangements which I have evolved.

Referrin now more particularly to Fig. 1,

' it'will be 0 served that the tops of the side frame piecesj6are milled off fiat from end to end, as indicated at 26. The tops of the bosses 27' arealso preferably milled ofi in the same operation. The latter provide guides for depending portions 28 ofthe journal bearings V 24 to permit vertical movement of the ournal.

bearings'when the jack screws 25 are adjusted. Pad portions29 of pressure bars 30 disposed between the drums 17 and 18 and between the drums 18 and 19 are arranged to be bolted; as indicated at 31, onto the flat top surface 26 of the side frame pieces. The corners of the pads 29 are relieved, as indicated at 32 to admit a shank 33 which depends from each of the journal bearings 24 and is formed integral with the portions28, previously referred to. Two other pressure bars 34 and 35 I are providedin front of the front drum 17 r and behind the rearmost drum -19, respecpads 36 to permit of a certain amount of joging of thebars 34 and 35 one way or another fora purpose which will presently appear. The journal bearings 24have walls 39 preferably-{formed integral therewith to enclose the sides of the drums and serve in the nature of guards. These side walls are flanged, as at 40, and provide a flat top surface for the bolting onto the bearings of top plates 41. These plates extend lengthwise of the drum and serve rigidly to interconnect the journal bearings 24 at the opposite ends of each of the drums, the said plates being bolted to the flanges 40 formed integral with said bearings in the manner shown. The top plates also provide vertical bearing surfaces 42 at the fore and aft sides thereof. These bearing surfaces on each of the plates 41 are arrarwed to be brought into close contact with silni ar bearing surfaces on adjoining plates, the plates being disposed in side to side relation in the manner shown. The engagement is such, however, as to permit of the vertical adjustment of one journal bearing relative to another. In other words, one top plate slides with respect to the other in the event one drum is adjusted relative to another. Taking drum 18 as an example for the present it will be apparent that a three-point support is provided for the journal bearing 24, the one point being directly beneath the ournal hearing at bearing 27 and the other two points being fore and aft with respect thereto at the surface 42. Obviously this makes for extreme rigidity and there is little likelihood of vibration and chattering of the drum in operation.

Any fore and aft thrust on the journal hearing incident to the operation of the drum is assumed mainly by the abutment of the fore and aft vertical earing surfaces. As respects the group of drums the journal bearings thereof obviously have mutual. support one from another by reason of the inter-engagement of the vertical bearing surfaces. The pressure bars 34 and 35 are extended into the plane of the top plates 41 and provide vertical end bearings at 43 and 44, respee tively, arranged to be brought up against the group of inter-supported bearings from in front and from behind to support the group as a unit against fore and aft play so as further to insure rigidity in the mounting of the drums and eliminate chattering and vibration in the operation thereof. The purpose in providing for a slight jogging of the pressure bars 34 and 35 will now be apparent. This jogging takes care of any discre )ancy in the machining of the plates 41 or discrepancies arising from other causes and permits the group of parts to be brought together into snug engagement for the purpose referred to. The three-point supporting of each pair of journal bearings is obviously unaffected by verticaladjustment thereof and the drum issupported as well in one state of adjustment as in another.

Referring now more particularly to Figs. 2 and 3 it will be observed that the top plates 41 are conformed to extend in between the drums over the tops of the pressure bars 30,

llltl communicate with both sides of the pressure eating with the exhaust opening 49.

bars 30 so that dust is exhausted from behind the drum 17 and the front of the drum 18 in one case, and from behind the drum 18 and the front of the drum 19 in the other case.

A hood is indicated in dotted lines at 47 fitting onto a hollow neck 48 provided at the juncture of the plates 41 about the exhaust openings 46. In the case of the front drum 1? a dust exhaust opening 49 is provided between the plate 41 and the pressure bar 34 communicating with the frontof the drum 17. Another hood 47 is provided communianother exhaust opening 50 is provided between the pressure bar and the plate 41 which abuts the same. This opening, like the others, exhausts through a hood 47 but in addition to its having communication with the back of the drum 19 this opening is in communication through a passage 51 with a brush chamber 52 provided in the pressure bar 35 for the reception of the work dusting brush 14. Thus, the exhaust opening 50 serves to remove dust from the back of the drum 19 and the front of the brush 14. This method of exhausting the dust from the back as well as the front of each drum, which forms the subject matter of another application, results in greater abrading efficiency and also in an improved character of finish produced on the work. The bulk of the dust is, of course, drawn off at the front of each drum. Any remaining dust particles which may become lodged in the abrading surface are subjected to a considerable centrifugal action from the time they pass the front exhaust opening up to the time they arrive at the rear exhaust opening and they are quite readily drawn off when subjected to a second draft at the rear exhaust opening. Manifestly, the abrading surface which comes into contact with. the work is, therefore, much cleaner than would otherwise be the case and this, of course, makes for the maximum efficiency and for the production of a smoother cut.

I claim:

1. In a drum type sander, the combination with frame members and rotary abrading drums having journals arranged to be supported on said frame members, of bearings receiving said journals, said bearings having parts extending downwardly therefrom, guides provided on the frame members arsan , ranged to receive said parts to provide one support for the bearings, means having connection with said parts for raising and lowering the bearings relative to theframe memhers, said bearings having parts extending fore and aft with respect thereto, the said parts of the groups of bearings being in contact with one another whereby to provide mutual lateral support for the bearings, and parts reaching upwardly from the frame members at the front and back of the machine and having the last mentioned parts at the front and back of the machine contacting therewith whereby the groups of bearings receive lateral support from the frame members.

2. In a drum type sander, the combination with frame members and rotary abrading drums having journals arranged to be supported on said frame members, of bearings receiving said ournals, means acting between the frame members and said bearings for raising and lowering the latter with respect to the frame members, said bearings having parts extending downwardly therefrom, guides provided on the frame members reeeiving said parts whereby to provide one support for the bearings, top plates extending over the drums lengthwise thereof and each rigidly connected at the opposite ends thereof to the bearings at the opposite ends of a drum whereby rigidly to interconnect the bearings, said top plates having bearing contact with one another on the fore and aft sides thereof whereby to provide mutual lateral support for the bearings, and abutments at the front an d back of the machine carried by the frame members having bearing contact with the front of the foremost top plate and the back of the rearmost top plate for the lateral support of the groups of bearings.

8. In a drum type sander, the combination with frame members and rotary abrading drums having journals arranged to be sup ported by the frame members, of bearings receiving said journals, means acting between the bearings and the frame members for raising and lowering the bearings relative to the frame members and supporting the same in adjusted positions, top plates extending over the drums lengthwise thereof and fastened at the ends to the bearings whereby rigidly to interconnect the pairs of bearings for the separate drums, said top plates being in bearing contact with one another fore and aft with respect to the bearings whereby to provide mutual lateral support for the bearings, and pressure bars mounted on the frame members between the abrading drums as well as in front of the foremost andbehind the rearmost drum, the foremost pressure bar being conformed to provide a bearing face for contact with the front of the foremost top plate and the rearmost pressure bar being conformed to provide a bearing face for contact of bearings.

with theback of the rearmost top plate whereby to provide lateralsupport for the groups I 4. A machine as set forth in claim 3 wherein the frame members provide flat top surfaces forthe reception of paid portions of the pressure bars, the said pad portions beingbolted rigidly to the frame members on said top surfaces, and wherein the foremost and rearmost pressure bars have elongated bolt holes in the pad portions thereof for the reception of the bolts for securing the same whereby said bars. may be adjusted relative to one another substantially as and for the purposes herein described. I

5. In a drum type sander, the combination with frame members and rotary abrading drumshaving end journals arranged to be supported by the frame members, of bearings receiving said journals, means acting between the bearings and the frame members for raising and lowering the same with respect to said frame members, top plates extending over the drums lengthwise thereof and fastened rigidly at the opposite ends thereof to the bearings, whereby each pair of bearings for a drum are rigidly interconnected, said'top plates having fore and aft bearing surfaces disposed in contact with one another between the drums for the mutual lateral support of the bearings, the said top plates being cut away at the bearing surfaces and having neck portions provided about the cut away portions adapted for connection with dust exhaust conduits, and abutments at the front and back of the machine carried b the frame members and having contact with the front of the foremost top plate and the back of the rearmost top plate respectively, whereby to provide lateral support for the groups of bearings.

6. In a drum type sander, the combination with frame members and rotary abrading drums having journals arranged to be supported on said frame members, of bearings receiving said journals, means for raising and lowering the latter with respect to the frame members and supporting the same in adjusted positions, top plates extending over the drums lengthwise thereof and each rigidly connected at the opposite ends thereof to the bearings at the opposite ends of a drum whereby rigidly to interconnect the hearings, said top plates having bearing Contact with one another on the fore and aft sides thereof whereby to provide mutual lateral support for the bearings, and abutments at the front and back of the machine carried by the frame members having bearing contact with the front of the foremost top plate and the back of the rearmost top plate for the lateral support of the groups of bearings.

In witness of the foregoing I ailix my signature.

PETER A. SOLEM. 

